Emphysema gradually damages the air sacs (alveoli) in your lungs, making you progressively more short of breath. Emphysema is one of several diseases known collectively as chronic obstructive pulmonary disease (COPD).

Smoking is the leading cause of emphysema.

Your lungs' alveoli are clustered like bunches of grapes. In emphysema, the inner walls of the air sacs weaken and eventually rupture — creating one larger air space instead of many small ones. This reduces the surface area of the lungs and, in turn, the amount of oxygen that reaches your bloodstream.

When you exhale, the damaged alveoli don't work properly and old air becomes trapped, leaving no room for fresh, oxygen-rich air to enter. Treatment may slow the progression of emphysema, but it can't reverse the damage.

You can have emphysema for many years without noticing any signs or symptoms. The main symptom of emphysema is shortness of breath, which usually begins gradually. You may start avoiding activities that cause you to be short of breath, so the symptom doesn't become a problem until it starts interfering with daily tasks. Emphysema eventually causes shortness of breath even while you're at rest.

When to see a doctor

See your doctor if you've had unexplained shortness of breath for several months, especially if it's getting worse or it's interfering with your daily activities. Don't try to attribute it to your deconditioning or age or weight. Seek immediate medical attention if:

You're so short of breath, you can't climb stairs

Your lips or fingernails turn blue or gray with exertion

You're not mentally alert

The main cause of emphysema is long-term exposure to airborne irritants, including:

Tobacco smoke

Marijuana smoke

Air pollution

Manufacturing fumes

Rarely, emphysema is caused by an inherited deficiency of a protein that protects the elastic structures in the lungs. It's called alpha-1-antitrypsin deficiency emphysema.

Factors that increase your risk of developing emphysema include:

Smoking. Emphysema is most likely to develop in cigarette smokers, but cigar and pipe smokers also are susceptible. The risk for all types of smokers increases with the number of years and amount of tobacco smoked.

Age. Although the lung damage that occurs in emphysema develops gradually, most people with tobacco-related emphysema begin to experience symptoms of the disease between the ages of 40 and 60.

Exposure to secondhand smoke. Secondhand smoke, also known as passive or environmental tobacco smoke, is smoke that you inadvertently inhale from someone else's cigarette, pipe or cigar. Being around secondhand smoke increases your risk of emphysema.

Occupational exposure to fumes or dust. If you breathe fumes from certain chemicals or dust from grain, cotton, wood or mining products, you're more likely to develop emphysema. This risk is even greater if you smoke.

Exposure to indoor and outdoor pollution. Breathing indoor pollutants, such as fumes from heating fuel, as well as outdoor pollutants — car exhaust, for instance — increases your risk of emphysema.

People who have emphysema are also more likely to develop:

Collapsed lung (pneumothorax). A collapsed lung can be life-threatening in people who have severe emphysema, because the function of their lungs is already so compromised. This is uncommon but serious when it occurs.

Heart problems. Emphysema can increase the pressure in the arteries that connect the heart and lungs. This can cause a condition called cor pulmonale, in which a section of the heart expands and weakens.

Large holes in the lungs (giant bullae). Some people with emphysema develop empty spaces in the lungs called bullae. Giant bullae can be as large as half the lung. In addition to reducing the amount of space available for the lung to expand, giant bullae can increase your risk of pneumothorax.

Your first appointment to check for emphysema may be with your primary doctor or with a specialist in lung diseases (pulmonologist).

What you can do

Before your appointment, you might want to write a list that answers the following questions:

Do you smoke? If so, how many packs a day and when did you start?

Are you exposed to the smoke of other smokers?

Have any of your jobs exposed you to chemical fumes or industrial dust?

Does anyone else in your family have lung problems?

What medications and supplements do you take regularly?

What to expect from your doctor

Your doctor may ask some of the following questions:

Do you cough every day? If so, when did that start?

If you smoke, have you tried to quit?

When did you first notice shortness of breath?

Does anyone in your family have emphysema?

Does shortness of breath keep you from completing daily tasks?

Have you ever noticed your fingernails or lips turning blue?

Have you recently gained or lost weight?

To determine if you have emphysema, your doctor may recommend a variety of tests.

Imaging tests

A chest X-ray can help support a diagnosis of advanced emphysema and rule out other causes of shortness of breath. But the chest X-ray can also show normal findings if you have emphysema. Computerized tomography (CT) scans combine X-ray images taken from many different directions to create cross-sectional views of internal organs. Your doctor may want you to have a CT scan if you're considering lung surgery.

Lab tests

Blood taken from an artery in your wrist can be tested to determine how well your lungs transfer oxygen into, and remove carbon dioxide from, your bloodstream.

Lung function tests

These noninvasive tests measure how much air your lungs can hold and how well the air flows in and out of your lungs. They can also measure how well your lungs deliver oxygen to your bloodstream. One of the most common tests uses a simple instrument called a spirometer, which you blow into.

Emphysema can't be cured, but treatments can help relieve symptoms and slow the progression of the disease.

Medications

Bronchodilators. These drugs can help relieve coughing, shortness of breath and breathing problems by relaxing constricted airways, but they're not as effective in treating emphysema as they are in treating asthma or chronic bronchitis.

Inhaled steroids. Corticosteroid drugs inhaled as aerosol sprays may help relieve shortness of breath. Prolonged use may weaken your bones and increase your risk of high blood pressure, cataracts and diabetes.

Antibiotics. If you develop a bacterial infection, like acute bronchitis or pneumonia, antibiotics are appropriate.

Therapy

Pulmonary rehabilitation. A pulmonary rehabilitation program can teach you breathing exercises and techniques that may help reduce your breathlessness and improve your ability to exercise.

Nutrition therapy. You'll also receive advice about proper nutrition. In the early stages of emphysema, many people need to lose weight, while people with late-stage emphysema often need to gain weight.

Supplemental oxygen. If you have severe emphysema with low blood oxygen levels, using oxygen regularly at home and when you exercise may provide some relief. Many people use oxygen 24 hours a day. It's usually administered via narrow tubing that fits into your nostrils.

Surgery

Depending on the severity of your emphysema, your doctor may suggest one or more different types of surgery, including:

Lung volume reduction surgery. In this procedure, surgeons remove small wedges of damaged lung tissue. Removing the diseased tissue helps the remaining lung tissue expand and work more efficiently and helps improve breathing.

Lung transplant. Lung transplantation is an option if you have severe emphysema and other options have failed.

If you have emphysema, you can take a number of steps to halt its progression and to protect yourself from complications:

Stop smoking. This is the most important measure you can take for your overall health and the only one that might halt the progression of emphysema. Join a smoking cessation program if you need help giving up smoking. As much as possible, avoid secondhand smoke.

Avoid other respiratory irritants. These include fumes from paint and automobile exhaust, some cooking odors, certain perfumes, even burning candles and incense. Change furnace and air conditioner filters regularly to limit pollutants.

Protect yourself from cold air. Cold air can cause spasms of the bronchial passages, making it even more difficult to breathe. During cold weather, wear a soft scarf or a cold-air mask — available from a pharmacy — over your mouth and nose before going outside, to warm the air entering your lungs.

Prevent respiratory infections. Get pneumonia vaccinations as advised by your doctor. Also get an annual flu shot. Do your best to avoid direct contact with people who have a cold or the flu. If you have to mingle with large groups of people during cold and flu season, wear a face mask, wash your hands frequently and carry a small bottle of hand sanitizer to use when needed.

The shortness of breath associated with emphysema can severely limit your ability to participate in daily activities. Many people become withdrawn and depressed. To help you cope with the changes emphysema has made in your life, you might want to:

Express your feelings. Your emphysema may limit some of your activities and affect your family's plans and routines in ways you can't always anticipate. If you and your family can talk openly about each other's needs, you'll be better able to meet the challenges of living with this disease. Be alert to changes in your mood and your relations with others, and don't be afraid to seek counseling.

Consider a support group. You may also want to consider joining a support group for people with emphysema. Although support groups aren't for everyone, they can be a good source of information about new treatments and coping strategies. And it can be encouraging to spend time with other people in circumstances similar to yours. If you're interested in a support group, talk to your doctor. Or contact your local chapter of the American Lung Association.

To prevent emphysema, don't smoke and avoid breathing secondhand smoke. Wear a mask to protect your lungs if you work with chemical fumes or dust.

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